1. Field of the Invention
The present invention relates to a memory circuit for reading and writing data from and into a nonvolatile memory element, and a voltage detection circuit including the memory circuit.
2. Description of the Related Art
In recent years, nonvolatile memory elements are used for various electronic devices.
For example, although not illustrated, a plurality of nonvolatile memory elements are arranged in matrix. In reading data, a read circuit is electrically connected to a nonvolatile memory element to read the data. When the reading of data is completed, the read circuit is disconnected from the nonvolatile memory element. In this case, the read data is latched in the read circuit.
As illustrated in FIG. 10, data in a nonvolatile memory element is suitably read to an internal circuit of an integrated circuit (IC) and used to change the setting of the circuit. Nonvolatile memory elements 109 and 110 are provided as a pair. A write circuit 105 writes data into the nonvolatile memory elements 109 and 110 so that the nonvolatile memory element 110 has a logical value “1” in a case where the nonvolatile memory element 109 has a logical value “0”. A read circuit 106 reads data from the nonvolatile memory elements 109 and 110 at a predetermined timing (see, for example, Japanese Patent Application Laid-open No. 2008-123644 (FIG. 2)).
In the conventional technology, a memory circuit requires separately the write circuit 105 and the read circuit 106. Therefore, a circuit scale of the memory circuit becomes lager.